The Collaborative International Dictionary of English v.0.48:

Directory \Di*rect"o*ry\, a. [L. directorius.]
   Containing directions; enjoining; instructing; directorial.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Directory \Di*rect"o*ry\, n.; pl. Directories.
   1. A collection or body of directions, rules, or ordinances;
      esp., a book of directions for the conduct of worship; as,
      the Directory used by the nonconformists instead of the
      Prayer Book.
      [1913 Webster]

   2. A book containing the names and residences of the
      inhabitants of any place, or of classes of them; an
      address book; as, a business directory.
      [1913 Webster]

   3. [Cf. F. directoire.] A body of directors; board of
      management; especially, a committee which held executive
      power in France under the first republic.
      [1913 Webster]

   4. Direction; guide. [R.] --Whitlock.
      [1913 Webster]

WordNet (r) 3.0 (2006):

directory
    n 1: an alphabetical list of names and addresses
    2: (computer science) a listing of the files stored in memory
       (usually on a hard disk)

Moby Thesaurus II by Grady Ward, 1.0:

149 Moby Thesaurus words for "directory":
   Almanach de Gotha, Baedeker, British Cabinet, Red Book,
   Royal Kalendar, Sanhedrin, Social Register, US Cabinet,
   Yellow Pages, account, acquaintance, advisory body, announcement,
   assembly, association, atlas, bench, bibliography, blue book,
   board, board of directors, board of regents, board of trustees,
   body of advisers, borough council, brain trust, briefing, bulletin,
   business directory, cabinet, cadre, calendar, camarilla, casebook,
   catalog, catalogue raisonne, chamber, checklist, city council,
   city directory, classified catalog, classified directory,
   common council, communication, communique, concordance, conference,
   congress, consultative assembly, council, council fire,
   council of ministers, council of state, council of war,
   county council, court, cyclopedia, data, datum,
   deliberative assembly, diatesseron, dictionary catalog, diet,
   directorate, dispatch, divan, encyclopedia, enlightenment,
   evidence, executive arm, executive committee, executive hierarchy,
   facts, factual information, familiarization, finding list,
   gazetteer, gen, genealogy, general information, governing board,
   governing body, guidebook, handbook, handlist, handout,
   hard information, harmony, incidental information, index, info,
   information, infrastructure, instruction, intelligence,
   interlocking directorate, itinerary, junta, kitchen cabinet,
   knowledge, legislature, light, management, mention, message,
   notice, notification, parish council, pedigree, phone book,
   polyglot, presentation, privy council, promotional material, proof,
   publication, publicity, record book, reference book, release,
   report, road map, roadbook, sidelight, source book, soviet, staff,
   statement, steering committee, studbook, syndicate, synod,
   telephone book, telephone directory, the administration, the brass,
   the dope, the executive, the goods, the know, the people upstairs,
   the scoop, top brass, transmission, tribunal, white book,
   white paper, word, work of reference



The Free On-line Dictionary of Computing (30 December 2018):

directory
directories
folder

    A node in a hierarchical file system which
   contains zero or more other nodes - generally, files or
   other directories.

   The term "folder" is sometimes used in systems such as the
   Macintosh or Microsoft Windows in which directories are
   traditionally depicted as folders (like small briefcases).

   (2007-02-21)


Bouvier's Law Dictionary, Revised 6th Ed (1856):

DIRECTORY. That which points out a thing or course of proceeding; for
example, a directory law.